/* CSS 樣式 - 深色模式 */
:root {
    /* 主色調 */
    --color-background: #1e1e1e; /* 主要背景色 */
    --color-container: #2c2c2c; /* 容器背景色 */
    --color-text-light: #f4f4f4; /* 淺色文字 */
    --color-text-dark: #bbbbbb; /* 深色輔助文字 */
    --color-shadow: rgba(0, 0, 0, 0.4); /* 陰影色 */
    --color-border: #444444; /* 邊框線 */

    /* 八度色 */
    --color-high-octave: #e74c3c; /* 紅色 (高音) */
    --color-normal-octave: #3498db; /* 藍色 (中音) */
    --color-low-octave: #2ecc71; /* 綠色 (低音) */

    /* 播放控制色 */
    --color-play: var(--color-low-octave);
    --color-pause: #f39c12; /* 橘色 */
    --color-stop: var(--color-high-octave);
    --color-export: #9b59b6; /* 紫色 */
}

body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: var(--color-background); /* 應用深色背景 */
    color: var(--color-text-light);
}

.container {
    text-align: center;
    padding: 30px;
    border-radius: 12px;
    background-color: var(--color-container); /* 應用深色容器 */
    box-shadow: 0 8px 16px var(--color-shadow);
    width: 90%;
    max-width: 950px;
}

h1 {
    color: var(--color-text-light);
    margin-bottom: 30px;
    text-shadow: 0 1px 2px var(--color-shadow);
}

/* 鍵盤佈局 */
.keyboard {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 30px;
    justify-content: center;
}

.octave-row {
    display: flex;
    gap: 5px;
    justify-content: center;
}

.key {
    padding: 15px 12px;
    width: 85px;
    font-size: 1.1em;
    font-weight: bold;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    color: white;
    transition: background-color 0.1s ease, transform 0.05s ease;
    box-shadow: 0 3px 0 var(--color-shadow);
}

/* 鍵盤顏色覆寫 */
.high-octave { background-color: var(--color-high-octave); box-shadow: 0 3px 0 #a93a31; }
.high-octave:active { background-color: #a93a31; transform: translateY(2px); box-shadow: 0 1px 0 #a93a31; }

.normal-octave { background-color: var(--color-normal-octave); box-shadow: 0 3px 0 #2071a9; }
.normal-octave:active { background-color: #2071a9; transform: translateY(2px); box-shadow: 0 1px 0 #2071a9; }

.low-octave { background-color: var(--color-low-octave); box-shadow: 0 3px 0 #1e8449; }
.low-octave:active { background-color: #1e8449; transform: translateY(2px); box-shadow: 0 1px 0 #1e8449; }

/* 控制面板 */
.controls-panel {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 15px;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    background-color: #363636; /* 略淺於容器的背景 */
}

.bpm-control label, .bpm-control input {
    color: var(--color-text-light);
}
.bpm-control input {
    background-color: #4f4f4f;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    padding: 5px;
    color: white;
}

/* 踏板控制 */
.pedal-control button {
    padding: 8px 15px;
    font-size: 0.9em;
    font-weight: bold;
    cursor: pointer;
    border: 1px solid var(--color-border);
    border-radius: 3px;
    margin-left: 5px;
    background-color: #555;
    color: var(--color-text-light);
    transition: background-color 0.1s;
}

.pedal-control button.active {
    background-color: #00bcd4; /* 啟用時使用亮青色 */
    color: black;
    font-weight: bolder;
}

.sequence-player {
    padding-top: 20px;
    border-top: 1px solid var(--color-border);
}

.note-legend {
    list-style: none;
    padding: 0;
    margin-bottom: 15px;
    text-align: left;
    font-size: 0.9em;
    color: var(--color-text-dark); /* 輔助文字使用較暗顏色 */
}

.sequence-input-group {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    margin-bottom: 15px;
}

/* -------------------------- 輸入框和顯示框 -------------------------- */

#playbackDisplay {
    min-height: 30px;
    padding: 10px 5px; 
    margin-bottom: 10px; 
    border: 2px solid var(--color-play); 
    border-radius: 5px;
    background-color: #3d3d3d; /* 顯示區塊使用較亮的深灰 */
    text-align: center;
    
    font-size: 1.8em; 
    font-family: monospace; 
    display: inline-block; 
    min-width: 8em; 
    
    font-weight: bold;
    color: var(--color-play);
    user-select: none; 
    transition: background-color 0.1s;
    align-self: center; 
    box-shadow: inset 0 0 5px rgba(46, 204, 113, 0.5); /* 內陰影強調 */
}

#playbackDisplay.active {
    background-color: #4f4f4f;
}

.button-group {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 10px; 
}

#noteSequenceInput {
    width: 100%;
    min-height: 80px;
    padding: 10px;
    margin-bottom: 10px; 
    border: 1px solid var(--color-border);
    border-radius: 5px;
    font-size: 1em;
    font-family: monospace; 
    line-height: 1.4;
    resize: none;
    box-sizing: border-box;
    background-color: #363636; /* 與控制面板背景一致 */
    color: var(--color-text-light);
    box-shadow: none;
}

/* ---------------------------------------------------------------- */

.sequence-player button {
    padding: 10px 20px;
    font-size: 1em;
    font-weight: bold;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    color: white;
    transition: background-color 0.1s ease;
    flex-grow: 1;
    max-width: 120px;
    box-shadow: 0 3px 0 rgba(0, 0, 0, 0.2);
}

#playButton { background-color: var(--color-play); }
#playButton:hover { background-color: #27ae60; }

#pauseButton { background-color: var(--color-pause); }
#pauseButton:hover { background-color: #e67e22; }

#stopButton { background-color: var(--color-stop); }
#stopButton:hover { background-color: #c0392b; }

#exportWavButton { background-color: var(--color-export); }
#exportWavButton:hover { background-color: #8e44ad; }

.sequence-player button:disabled {
    background-color: #5d6d7e;
    color: #aeb6bf;
    cursor: not-allowed;
}